INFO: task syz.0.722:6667 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.722 state:D stack:26224 pid:6667 ppid:4267 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747
sync_bdevs+0x1ab/0x320 block/bdev.c:1071
ksys_sync+0xc2/0x170 fs/sync.c:105
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6a3cd9aeb9
RSP: 002b:00007f6a3db81028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f6a3d015fa0 RCX: 00007f6a3cd9aeb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f6a3d015fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a3d016038 R14: 00007f6a3d015fa0 R15: 00007ffef751b5a8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2dfb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e7d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
3 locks held by kworker/1:2/127:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90002d37d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#2: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
2 locks held by kworker/1:3/3596:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000dcbfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4028:
#0: ffff88802fbfe098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
1 lock held by udevd/4274:
#0: ffff88814433b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832
2 locks held by kworker/0:13/5592:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900049dfd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by syz.0.722/6667:
#0: ffff88814433b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1071
1 lock held by syz-executor/6948:
#0: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
2 locks held by rm/9756:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9729 Comm: dhcpcd-run-hook Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:mark_usage kernel/locking/lockdep.c:4501 [inline]
RIP: 0010:__lock_acquire+0xb8a/0x7d10 kernel/locking/lockdep.c:5003
Code: df 85 c0 74 25 48 c7 c0 e8 f7 1f 8e 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 88 62 00 00 83 3d f4 a6 bb 0c 00 0f 84 bf 0f 00 00 <83> 7c 24 34 00 4c 8b 74 24 78 0f 84 d4 01 00 00 48 8b 44 24 50 42
RSP: 0018:ffffc9000e956e60 EFLAGS: 00000093
RAX: 0000000000000003 RBX: 0000000000000003 RCX: 0000000000000003
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af32e8
RBP: ffffc9000e9570b0 R08: dffffc0000000000 R09: 1ffffffff215e65d
R10: dffffc0000000000 R11: fffffbfff215e65e R12: ffff88802f8ed940
R13: 0000000000000003 R14: ffffffff904ba1b8 R15: ffff88802f8ee4b8
FS: 00007f8ba5cb1c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8ba5f525b8 CR3: 00000000651ee000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
page_ext_get+0x3a/0x2a0 mm/page_ext.c:157
__page_table_check_zero+0x134/0x4b0 mm/page_table_check.c:146
prep_new_page mm/page_alloc.c:2539 [inline]
get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4328
__alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5614
__get_free_pages mm/page_alloc.c:5664 [inline]
get_zeroed_page+0x13/0x30 mm/page_alloc.c:5673
__pud_alloc_one include/asm-generic/pgalloc.h:156 [inline]
pud_alloc_one include/asm-generic/pgalloc.h:171 [inline]
__pud_alloc+0x31/0x150 mm/memory.c:5463
pud_alloc include/linux/mm.h:2424 [inline]
copy_pud_range mm/memory.c:1194 [inline]
copy_p4d_range mm/memory.c:1238 [inline]
copy_page_range+0x3506/0x3900 mm/memory.c:1332
dup_mmap kernel/fork.c:702 [inline]
dup_mm kernel/fork.c:1546 [inline]
copy_mm+0xec3/0x1690 kernel/fork.c:1595
copy_process+0x1979/0x4030 kernel/fork.c:2356
kernel_clone+0x24b/0x900 kernel/fork.c:2762
__do_sys_clone kernel/fork.c:2903 [inline]
__se_sys_clone kernel/fork.c:2887 [inline]
__x64_sys_clone+0x1a7/0x220 kernel/fork.c:2887
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8ba5e4b636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffe6b9175b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe6b9175b8 RCX: 00007f8ba5e4b636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 000056133aa3dc30 R08: 0000000000000000 R09: 0000000000000001
R10: 00007f8ba5cb1f50 R11: 0000000000000246 R12: 000056133aa52e80
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000